Gas engine



oct. 15, 1940. E. M. LINDSEY 2,217,912

GAS ENGINE Filed sept. 2e, 19'39- 4 sheets-sheet 1 ,4 ,III- 2 iIiI-I; I l I l v FIG-EI l s v auf caMPLn-f cvcus 9 new 7 \\\\"\'J al alla FIEr. E 82 I M, e @Je Arraf/vfyf Oct. 15, 1940. E, M, .NDSEY 2,217,912

GAS ENGINE Filed sept. 26,-1939 v 4 sheets-sheet 2 4 Sheets-Sheet 3 GAS ENGINE Filed Sept. 26, 1939' E. M. LlNDsEYI wf/ETI@ LxNDsEY GAS ENGINE Filed sept. 26, 193s 4 sheets-sheer 4 r I/////////////////////// f Arran/vhs Patented Oct. 15, 1940 UNITED STATESl PATENT OFFICE A 14 Claims.

This invention relates to an internal combustion engine and more particularly to an internal combustion engine of the two-fcycle type and adapted especially to the burning of a highly volatile hydrocarbon such as gasoline. The invention comprehends an engine embodying in combination a number of features cooperating to produce an engine developing more power per unit of weight than engines heretofore known, an engine having longer life than previous engines, and an engine which is of less complex construction and more readily maintained in adjustment than the previously known engines.

It is an object of the present inventionto provide a two-cycle engine having opposed power developing pistons connected together by a yoke, the pistons and connecting yoke rmoving in a Ystraight line as distinguished from the conventional engine wherein the connecting rod is continually changing in direction; lin this way the Wear on the wrist pins is reduced to a practically negligible figure, and the sidewise thrust of the pistons upon the cylinders is eliminated.

Another object is to provide an engine of the type just described wherein the crank pin rotatably engages a crosshead, sliding within the yoke connecting the power developing pistons.

Still another object is to devise an engine of the foregoing type in which the yoke connecting the power pistons is also attached to pumping pistons operating within pumping cylinders disposed adv jacent the power cylinders, the pumping pistons traveling in exact step with the power pistons fed by the pumping pisto s.

Another object is t y devise a valve mechanism preferably carried in a detachable valve head and which embodies only a single valve for the pumping cylinder, the intake valve for the power cylinder serving also as the exhaust valve for the pumping cylinder, whereby the number of valves required is reduced and the initial cost and the cost of maintenance of the engine are likewise reduced.

Still another object is to provide a timing gear which is rotatably journaled over the valve head and which is provided with circular cam surfaces 'engaging the respective valve stem ends; in a preferred form, each cam surface of the timing gear is provided witha plurality of valve operating surfaces, whereby the speed of rotation of the timing gear is reduced in proportion, and the) wear on the timing gear on the cam surfaces therewith, and upon the timing gear operating mechanism is materially reduced, while at the same time the power required to operate the timing cam gear is also reduced.

Another object is to provide an engine having a ltiming gear which carries on one face thereof these cam surfaces being formed integral withV or (C1. 12ms) nxedly attached to the timing. gear bodmthus re,-A ducing the number of parts and eliminating, the:

conventional cam shaft attached to the usual timinggear; the 'invention also provides for the.

elimination of the usual tappetsl or push rod' avoidably present between the cam shaft and the` ends of the valves.

Still another object is to devise an engine of the foregoing type wherein provision is made for the positive lubrication of al1 of the working parts, and in apreferred embodiment wherein an oil pump of improved design is employed for lubricating the motor.

Other objects of the invention will more fully appear as the detailed description thereof proceeds.

In the drawings;

'Figure 1 is a plan view showing ,the general appearance of one form of motor embodying the principles of the present invention.

Figure 2 is a vertical transverse sectional view taken on the line 2 2 of Figure 1 at right angles to the crank shaft of the engine.

Figure 3 is a sectional view on the line 3 3 of Figure-2 showing the details of the connecting 'sliding crosshead and yoke therefor.

Figure 4 is a vertical longitudinal section taken on the line 4 4 of Figure 1 and along the crank shaft of the engine. v

Figure 5 is a detailed sectional view taken on the line 5 5 of Figure 4 looking in the direction of the arrows. This view shows details of the oil pump assembly.

Figure 6 is a central vertical section through the valve head, timing gear and end of the combustion and pumping chambers of one end of the engine.

Fig. 'I is a sectional view on the line 1 1 of Figure 6 looking in the direction of the arrows.

Figure 8 is a section on theline 8 8 of Figure 6 looking in the direction of the arrows and shows the appearance of the cylinder head from 'the inner face thereof.

Figure 9 is a diagramhowing thevalve opening and closing sequence of the engine of the present invention.

Figure 10v is a sectional view taken on the line lil-'l0 of Figure '4 looking in the direction of the arrows.

Figuren is a detailed sectional view on the'line Figure 13 is a detailed horizontal section showing the timing shaft and its connection to the valve operating timing gear at the outer end of the engine and to the gear mounted on the crank shaft which operates the-timing shafts. V

Figure 14 is an enlarged sectional view upon the'line I4-I4 of Figure 6 showing the details of the valve construction and of the valve adjusting arrangement.

Figure 15 is a section on the line I5-I5 of Figure 14 looking in the direction of the arrows and shows the means for obtaining an extremely iine adjustment of the effective valve length.

Figure 16 is a plan view of the underside of the timing gear, showing the cam surface for actuating the valves.

Referring to the drawings in detail, and iirst particularly to Figure 1, it will be observed that the engine illustrated is of the two cylinder horizontally opposed two-cycle type having a centrally disposed crank case designated generally as I, the construction of which will more fully appear below. The cylinder blocks 2 which are integral with crank case I project oppositely from.

this crank case and are of the airicooled type having the usual spaced air cooling ns. The valve heads designated generally as 3 are mounted upon the outward ends of the cylinder blocks 2. Housings 4 are mounted upon the outer faces of the valve heads 3 and serve to keep dirt and dust out of the valve operating mechanism as well as to provide a closed chamber for the circulation of oil over the valve mechanism. The crank case I comprises a rearwardlyextending flywheel housing 5 which is `preferably integral with crank case I and which serves in cooperation with a cover member 6 to form an enclosed flywheel chamber and a forwardly extending detachable fan housing 1 to the sides of which, as at 8, are attached air distributing hoods 9 adapted to lead the air from fan housing 1 outwardly and to then discharge it rearwardly over cylinder blocks 2 and the valve heads 3, thus ef- Y fectively cooling the same. 'I'he 'air distributing the combustion cylinders are indicated at I4 and' hoods 9, it will be understood, are enlarged rearwardly to some extent, and are. open at their'rear portion so as to discharge `the air rearwardly.

The propeller or drive shaft I0 is shown at the in them reciprocate the power pistons I5. Dis'- posed just above power cylinders' I5 are pumping cylinders I6 in which operate pumping lpistons I1. Pumping pistons I1 are provided with Wrist pins I8 pivotally engaged by one end of pumping connecting rods I9. Power pistons I5 have wrist pins 20 pivotally engaged by the outward ends of main connecting rods 2| which are consider-- ably stronger than connecting lrods I9 and which converge toward the crank pin. These connecting rods 2I are integral Aat their inner ends with vertical slide rail members 22, reinforcing integral members 23 being preferably provided between members 22 and 2|. The slide rail members 22 are connected at their upper and lower ends by means of curved channel-shaped yokes 24 so as to makeA a rigid slide frame for the sliding crank pin bearing. The inner faces of slide rail members 22 are concaved as at 25 (Figure 3) so as to provide a sliding and aligning surface for the split crank pin bearing. The crank shaft 28 (Figure 4) comprises the usual main bearing portions 21, crank arm portion 28 and crank pin 29. The crank pin 29 rotates in a'split bearing 30, the halves of which are carried on split members 3I which are made convex on their outer surface 32 to correspond with and be aligned by concave surface 25 of slide railI members 22. Crank pin bearing halves 3| are held together by means of bolts 33 which are provided (Fig. 3) with a shoulder portion 34 at one end, with a threaded portion 35, and with polygonal sockets 36 at their other end adapted to be engaged by an Allen wrench, whereby the split halves may be held together, threaded portion threadably engaging a threaded opening in the bearing half 3l. Each of the split halves 3| is provided with openings 31 to lighten the construction and to Iprovide access to the bolts 33 for assembly and disassembly.

The pumping piston connecting rods I9 are either pivotally or ilxedly attached to the upper ends of slide rail members 22, as at 38. Thus,

as the crank shaft 2B is rotated by the power impulses upon. pistons I5, the pumping pistons I1 are carried in step with power pistons I5 and the split crank pin bearing made of members 3| reciprocates vertically along slide rails 22, and in this way the slide rail assembly, connecting rods 2l, and pistons I5 andv I1 execute simple harmonic motion, instead of the approximation of simple harmonic motion obtained with the conventional connecting rod assembly. The wear upon wrist pins 2U and I8 is almost negligible since there is substantially no oscillation of the connecting rods around the wrist pins. Likewise, the sidewise thrust of the usual connecting rods upon the pistons with resulting uneven wear upon the pistons and cylinders is completely eliminated. `'I'he construction -of slide rails 22, and integral main connecting rods 2| coupled together hy the yoke members 24, provides an assembly which is strong and sturdy but light.

An oil pan 39 (Figures 2 and 4) is detachably secured to the lower portion of the crank case and serves as an oil reservoir for oil used in lubricating the engine. Figure 2 also illustrates the exhaust ,manifold 48 connected to the exhaust ports 4I of the valve heads 3.

` The crank arm portion 28 of the crank shaft (Figures 3 and 4) is merely one portion of circular members 42 which are cast integral with the crank shaft and comprises heavy portion 43 (Figure 4) designed to counterbalance the crank pin 29. Referring particularly to Figure 4, it will be seenv that a cooling fan 45 is carried on a ro- "tatingmember 4i keyed to the front end of crank shaft 2'6. The cooling fan is thus carried inside of fan housing 1 and rotates at the same speed as the crankshaft 28, Preferably, fan 45 comprises eight large fan blades in order to prevent the motor from overheating. The usual crank indicated in dotted lines 41 may be provided for manual cranking of the engine. yFlywheel 48 is fixedly attached to lthe rear end of the crank end 49 of driven shaft I0 is bolted tothe crank shaft flange U by means of boltsf5I which pass through suitable holes in flywheel 48, thus bolting the three members 48, 49 and 50 together to rotate as a unit. Flywheel housing member 6 may be provided, if desired, with a tapered roller bearing 52 for journaling driven shaft I0. Flywheel 48 may be toothed in the usual manner on its periphery for the engagement of the pinion 53 connected to a suitable starter. y

Valve heads 3 are finned transversely as indicated in Figures 1, 2 and 6, the cooling lflns on the valve heads being at right angles to the cooling fins on thecylinders 2, but the flns on the valve heads are adapted to have the air from the endmost portions of cooling hoods 9 pass over them in intimate contact with them.

Where possible, as indicated at 54 in Figures 2,

and 6, these cooling fins go all the way through valve heads 3, thus adding greatly to the cooling effect. Y. v

With particular reference now to Figures 6 to 8, it will be seen that the valve and cylinder heads 3 are attached to the cylinder blocks 2 by means of bolts 55, the usual gasket 56 being interposed therebetween. A combustion space 51 is provided over power piston I5 and Within the valve and cylinder head 3. A compressing space 58 is likewise provided over pumping piston I1. An exhaust valve 59 adapted to allow exhaust gases to be discharged through exhaust port 4I, and an intake valve 60 for combustion chamber 51 are provided.v The spark plug is indicated at 6i (Fig. l2) and is located at the forward side.

of the domed combustion chamber in 'order to allow the combustion space 5.1 to be as small as possible.

The pumping vcylinder I6 is provided with anv intake valve 62 which is adapted to allow the combustible mixture to be sucked in'from intake port i3. A passageway 63 leads from compressing space '58` to combustion cylinder inlet valve 60 whereby the compressed combustible mixture can be passed from the pumping cylinder into the combustion cylinder at the proper ltime.

Centrally disposed in the valve head 3 is an upstanding boss 64 into which is adapted to be fitted by shrinking a stubshaft 65 upon which is journaled by means of ball bearings 66 the tim# ing gear 61 which is located within the housing 41 housing 4 being attached by bolts 68 to a plate 69 which is attached to a flange 10 on the valve head casting 3 as by bolts 1I. The timing gear 61 is 4provided with peripheral teeth 12 which are enmeshed with a timing pinion 13 (Figure 13) xedly mounted on timing shaft 14 which is drivenby a beveled pinion in turn driven by a bevel gear 16 xedly mounted on crank shaft 26 (Figs. 4 and 13) A timing shaft housing 11 encloses the timing shaft 14 and is disposed between the crank case I and plate 69 in any suitable manner, bearings 18 of suitable type being .provided for timing shaft 14. As will be apparent, timing gear 61 will be adjusted with reference to the motor and the valves so as to give the propertiming of the engine which will be discussed below. Timing gear 61 is held on stubshaft 65 by means of nut 19. Timing gear 61 is provided on its inward face with circular cam surfaces which are adapted to engage the ends of the three valves at ea'ch end of the motor and to actuate thesame 1n proper sequence so as to cause proper operation of the motor. Timing gear 61 is rotated once every two revolutions of the crank shaft 26, and thus rotates at half the speed which would normally be imparted to the timing of a 2-cycle engine, and in this way 5 the wear on the timing gear and the drive therefor is materially reduced while at the same time the power required to drive it is also reduced.

This reduction in speed of timing gear 61 necessprings 83 engaging -shoulders 84 fixedly connected with the valves are provided for holding the valves normally closed. The spring 83 of inlet valve 66 is suiiiciently strong to prevent any leakage of gases compressed -by piston I1 into power cylinder I4 prior to the opening of valve 60 by its cam track 8|. The operation of the 25 engine and particularly of the valves thereof is illustrated in Figure 9 which portrays one complete cycle beginning with ignition in one end of the engine and ending with ignition in the same end of the engine. As the ignition impulse Atakes place, both the intake and exhaust valves of the combustion cylinder I4 remain closed for one-fourth of a stroke. The pump valve 62 opens simultaneously with ignition, thereby allowing combustible gas to be drawn in to the pumping cylinder I6 at the Sametime as a power impulse is generated in the power cylinder i4. The exhaust valve 59 of the power cylinder opens at the completion of one-fourth of a stroke, while the pump intake valve 62 re- 40 mains open until the power and pumping pistons have made one-half of a stroke. The pump intake valve 62 now closes while the power intake fvalve 60 remains closed and the exhaust valve 59 remains open. Upon the upstroke, the 45 pumping piston I1 compresses the combustible mixture thereabove to relatively high pressure Auntil it is halfway towards the top on the upstroke. At this point, the exhaust valve 59 is closed and the power inlet valve 60 is opened, 50,

allowing the highly compressed mixture above the pumping piston I1 to be discharged into the power cylinder under higher pressure than it would normally be. The pistons continue to move together until they reach the top of the upstroke, whereupon the intake valve 60 closes, substantiallyall of the combustible gas above piston I1 having been pumped into the space above power piston I5 under relativelyuhigh pressure, and the continued upward movement of piston I5 having served to further compress the combustible mixture above it. The parts are now in position for another cycle which Ais repeated in the same manner.

The ignition details other than the spark plugs 6I have notbeen indicated since they are con-- ventional and form no part of -the present invention. The ignition breaker may suitably be disposed within the fan wheel 46 and is so timed as to deliver a firing electrical impulse to the 70 spark plug 6I at the top dead center position of each cylinder at' each revolution thereof.

There will now be described the lubricating system of the engine shown in the drawings. Referring to Figure 4, it will be seen that an oil isi the oil is adapted to be sucked upwardly intol the housing 86 by means of slanting vanes 92 of the impeller 93 iixedly mounted on the lower.

end of oil pump shaft 81. The shaft 81 is provided with a central bore 94 uid connected to the supply of oil under pressure in casing 86 by means of dlverging bores 95. It will be seen that Y as the impeller 93 is rotated in the proper direction, it will cause oil to be sucked up through hole 9I and to be forced under pressure upwardly through bore 94. Bore 94 communicates with a bore 91 in the lower half 96 of the main bearing of the crankshaft. Bore 91 communi- ,A cates with a bore 98 in crank shaft 26, this bore 98 communicating with a bore 99 which lubricates the crank pin bearing 30. Suitable means is provided for allowing oil to escape from crank pin bearing 30 to lubricate the bearing surface formed between concave surface 25 and convex surface 32. The oil continues under pressure along the bore 98 to a bore 99 which lubricates the front main bearing which `is provided with a fluid pressure take oil as at IOI making fluid pressure connection with T-shaped member |02 to which are attached transversely extending valve head lubricating lines |03 (Fig. 1) entering the compartment |04 which serves as an oil chamber for oiling the valves and thel serted in the side of the crank case I in any suitable manner, being gasketed by means of fibrous gasket material |09 laid in grooves I I0 formed in the adiacent edges of the contacting surfaces. The two bearing halves 96 and |01 may be rigidly bolted together by means of bolts III, thereby transferring a good deal of the loadof the crank shaft to the crank case I. Plate |08 suitably carries by means of a lug II! the oil pump 85, and the extreme upper portion of oil pump shaft 81 may be journaled as at II4 in the lower main bearing half 96. Oil passing along the rear main bearing portion of the crank shaft may be received by a groove Il! and pass thence downwardly through a bore II6 to lubricate the bevel pinion 08 which in turn lubricates bevel gear'16l and thereby lubricates bevel pinion 15 of the tim" ing mechanism.

I prefer to use a valve constructed as shown in detail in Figures 14 and 15. 'I'he valve is made in two main parts, the main stem ||1 being threadably received within the portion I I8 which is adapted to engage the valve guides. Cylindrical portion |I8 is preferably provided with a pis.

ton'ring III which is adapted to prevent leakage of gas or oil between the valve and the valve guide and is also provided with the` outwardly extending portion |20 adapted to slidably engage the cam surfaces o f thetiming gear 61. The stem portion ||1 is enlarged as at |2| to form a firm support for the valve upon cylindrical member I I8, a shim |22 of suitable thickness being interposedbetween enlarged portion Y`I2| and the cylindrical portion II8.

To adjust the effective length of the valve, I provide enlarged portion |23 with transverse bores |24, and slot -the threaded end ofthe valve stem as at |25. whichis adapted to pass through any one of bores |24 and Ithrough slot |25 thereby holding the stem I I1 against rotative-movement with respect to cylinder portion IIS. By providing a plurality of radial bores |24, I am enabled to get an exceedingly fine adjustment of the eiective length of the valve. For example, by providing eight radial bores |24. it is possible to adjust the valve length in increments equal to one-eighth of the thread pitch of the threaded engagement between members II1 and II8. In order to maintain a firm interconnection between |2I and IIB in the adjusted position, a new shim |22 of proper thickness is inserted to Itake up the new clearance. In practice, a series of shims |22 of varying thickness will be provided to facilitate this adjustment during maintenance or overhaul of the engine, only that shim of proper thickness being used and the remaining shims being held y -31S 9. reserve.

Figure 16 shows in bottom plan view the timing gear 61 and illustrates how the cam ribs 80, 8| and 82 are formed with high points of the proper length to actuate the cams in accordance with the timing vsequence of Figure 9. The exhaust valve operating rib 80 is provided with a high surface |21 and a corresponding high surface |28 located 180 therefrom, so that the exhaust valve 59 isalternatively opened by high points |21 `and |28 which successively contact the same. High points |21 and |28 are each extended for one-fourth of the circumference of the rib 80, or for 90. Similarly, pump valve operating rib 82 is provided with high points |29 and |30 for actuating the pump valve 62, each of these high points |29 and |30 extending for one-fourth of the circumference of the circle, or' 90, and these high points |29 and |30 are similarly arranged in series so as to successively open pump valve 62. Likewise, rib 8| for actuating the inlet valve 60 of the combustion r pumping pistons which feed the adjacent combustion cylinders. It will be seen that by the use of the sliding cross-head and the elimination of the oscillationlof the connecting rodsA that I have provided an engine which is adapted to develop more horse power by reason of the elimination of friction and unnecessary thrusts. It will further be seen that .the provision of the improved timing mechanism for the engine of the foregoing type still further results in increasing the effec-- tive power of the engine and eliminating to a. large extent the maintenance costs of the previously employed engines.

I wish it to be understood that I desire to include'as within my invention such modifications as may be necessary to adapt the same to varying A locking pin |26 is provided conditions and uses andas fall within the terms and spirit of the appended claims,

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In an internal combustion engine, a combustion cylinder, a power piston therein, a pumping cylinder disposed alongside said combustion cylinder, a pumping piston in said pumping cylinder and arranged to travel in unison with said power piston, means for admitting a combustible gaseous mixture to said pumping cylinder as said pistons move on their downstroke and for exhausting spent gas from said combustion cylinder for at least one half of said stroke, means for preventing said gaseous mixture from escaping from said pumping cylinder when said pistons move on their upstroke and for continuing exhausting said gas for at least one-half of saidl stroke, and means for transferring the compressed gaseous mixture from said pumping cylinder vto said combustion cylinder as said pistons pass the half-way point in their upstroke to continue com,- pression of said gas by both pistons during the nal portion of said stroke.

2. In an internal combustion engine, a combustion cylinder, a power piston therein, a pumping cylinder disposed alongside said combustion cylinder, a pumping piston in said pumping cylinder and arranged to travel in unison with said power piston, means for admitting a combustible gaseous mixture to said pumping cylinder as said pumping piston moves on its downstroke and for preventing said gaseous mixture from escaping as said pumping piston moves on its upstroke, and means for transferring the compressed gaseous mixture from said pumping cylinder to said combustion cylinder as said pistons pass the halfway point in their upstroke vand for preventing the return iiow of the gaseous mixture so transferred after they reach the end of their upstroke and begin on the downstroke.

3. In a two-stroke-cycle internal combustion engine, a combustion cylinder, a power piston therein, a pumping cylinder parallel to said combustion cylinder and terminating substantially equally therewith, a pumping piston in said pumping cylinder, means for moving said pistons in their respective cylinders simultaneously and in stepv with one another, a passageway connecting the compression spaces of said cylinders, an inlet valve for said pumping cylinder, a common valve in said passageway serving as an outlet valve for said pumping cylinder and as an intake valve for said combustion cylinder, anexhaust valve for said vcombustion cylinder, said valves being 'so xtimed with respect to said pistons that as said pistons begin their downstroke said inlet valve is opened and said common valve closed whereby said pumping piston sucks in a charge of gas on its downstroke, that as said pistons pass the half-` way point in their downstroke said exhaust valve is opened, that as said pistons reach the bottom of their downstroke and begin their upstroke said inlet valve is closed while said common valve remains closed, whereby said pumping piston compresses said charge, that as said pistons pass the halfway point in their upstroke said common valve is opened and said exhaust valve is closed while said inlet valve remains closed whereby the charge compressed by said pumping piston is transferred to said combustion cylinder during the last half of the upstroke, and that as said pistons complete the upstroke said common valve is closed to prevent return of said charge.

4. In a twostroke-cycle internal combustion engine, a combustion cylinder, a power piston therein, a pumping cylinder therefor disposed parallel thereto and having its termination substantially commensurate therewith, a pumping piston in said pumping cylinder adapted to compress a charge of vcombustible gas and to deliver a charge so compressed to said combustion cylinder under pressure greater than said combustion cylinder would normally build up, connecting rods for said pistons, a cross member connecting said connecting rods adapted to reciprocate transversely therewith but to remain stationary longitudinally, a crankshaft having a crankpin, and means interconnecting said crankpin and said cross member for transmitting the transverse' component of movement of said crankpin to said cross member to cause transverse reciprocation thereof while allowing said crank pin free movement along said' cross member and substantially preventing the right angle component of movement of said crankpin from being transferred to said cross member.

5. In a two-stroke-cycle internal combustion engine, a combustion cylinder, a power piston, a pumping cylinder therefor disposed parallel thereto and terminating substantially therewith, a pumping piston therein,l connecting rods for said pistons, a crankshaft having a crankpin, a cross-member, means connecting said crankpin with said cross-member for causing said crossmember to be reciprocated bysaid crankpin but for allowing said crankpin to move freely along said cross-member, and means connecting one of said connecting rods to said cross-member for preventing relative motion between said crossmember and said connecting rod, the other of said connecting rods being secured to said cross-v member in such manner that the piston thereof is caused to reciprocate simultaneously with the other piston, whereby relative movement of said connecting rods with respect to said pistons is is in each of said pumping cylinders and is adapted to compress a gaseous charge and deliver it to its combustion cylinder, said pumping pistons and said power pistons moving in, step and in unison with eachother, a crankshaft, a crankpin thereof, a centrally disposed yoke comprising two parts retained in parallelism, said co-v operating power and pumping pistons being connected to opposite parallel parts of said yoke,

Aa crankpin bearing disposed on said crankpin4 and within said yoke in such manner that it is free to slide therein in a direction at right angles to' said cylinders and pistons, but is fixed therein against transverse and parallel movement to said cylinders, said power pistons moving said yoke reciprocally in parallel and planar alignment therewith While said crank pin bearing moves at right angles to vsaid plane whereby rotary movement is imparted to said crank pin.

7. In a two-stroke-cycle internal combustion engine, a combustion cylinder, a power piston therein, a pumping cylinder parallel thereto, a pumping piston therein operating in step with said power piston, a common cylinder head for said cylinders. an inlet valve in said head for said pumping cylinder, intake and exhaust valves in said head for said combustion cylinder, a transfer passageway in said head connecting said cylinders and valved by said intake valve, and a cam member rotating about an axis parallel to the axes of said valves and timed with respect to the movement of said pistons for operating said valves.

8. In'a two-stroke-cycle internal combustion engine, a combustion cylinder, a power piston therein, a pumping cylinder parallel thereto, a pumping piston therein operating in step with said powerpiston, a common cylinder head for said cylinders, an inlet valve in said head for said pumping cylinder, intake and exhaust valves in said head for said combustion cylinder, a transfer passageway in'said head connecting said cylinders and valved by said intake valve, said valves having actuating stems extending paral- 20 lelly outwardly, anda rotatable cam member journaled about an axis parallel to the axes of said valves and timed with respect to the movement of said pistons for operating said valves, said cam member having-circular cam surfaces on its inward face which are adapted to engage with the outward ends of said stems.

9. Ina two-stroke-cycle internal combustion engine, a combustion cylindez, a power piston therein, a pumping cylinder parallel thereto, a`

said power piston, a common cylinder head for said cylinders, an inlet valve in said head for said pumping cylinder, intake and exhaust valves in said h'ead for said combustion cylinder, a transfer passageway in said h ead connecting said cylinders and valved by said intake valve, said valves having actuating stems extending parallelly outwardly, and a rotatable cam member journaled about an axis parallel to the axes of said valves and timed with respect to the movement of said pistons for operating said valves, said cam member having circular cam surfaces on its inward face which are adapted to engage with the outward ends of said stemsiand rotating once every two full cyclesof the power cylinder and provided with two full series-arranged cam surfaces for each of said valves.

10. In a two-stroke-cycle internal combustion engine, a combustion cylinder, a power piston wtherein, a pumping cylinder parallel thereto, a

pumping piston therein operating in step with said power piston, s. common cylinder head for said cylinders, an inlet valve in said head' for said pumping cylinder, intake and exhaust valves u in said head for said combustion cylinder, a transfer passageway in said head connecting said cylinders and valved by said intake valve, said valves having actuating stems extending parallelly outwardly, and a rotatable cam member journaled about an axis parallel to the axes of said valves and timed with respect to the movement ofv said pistons for operating said valves, said cam member having circular cam surfaces on its inward face which are adapted tol engage with the outward ends of said stems, androtating once for a plurality of full cycles of the combustion cylinder and provided with the same number of full cam surfaces arranged in series for each ot I "said valves. 70 11. In an internal combustion engine, a combustion cylinder, a power piston therein, a pumping cylinder. a pumping piston therein, said pumping cylinder and piston being adapted to draw in a. combustible gaseous mixture and to compress the same, a fluid lubricating circuit for said engine, a valve head positioned upon said combustion and said pumping cylinders, valve means within said head for controlling the flow of a combustible mixture through said cylinders, cam means positioned within said head and associated with said valve means for timing the operations of said valve means, and means for connecting said valve head within the fluid lubricating circuit for said engine to cause lubrlcant from the engine to flow through said valve head.

12. In an internal combustion engine, a combustion cylinder, a power piston therein, a pumping cylinder, a pumping piston therein, said pumping cylinder and piston being adapted to draw in a combustible gaseous mixture and to compress the same, a fluid lubricating circuit for said engine, a valve head positioned upon said combustion and said pumping cylinders, valve means within said head for controlling the flow of a combustible mixture through said cylinders, a cam member rotating about an axis parallel to the axes of said valves for timing the operation of said valve means, and means for connecting said valve head within the fluid lubricating circuit for said engine to cause lubricant from the engine to iiow through said valve head.

13. Ink an internal combustion engine, a combustion cylinder, a power piston therein, a pumping cylinder, a pumping piston therein, said pumping cylinder and piston being adapted to draw in a combustibleY gaseous mixture and to compress the same, a fluid lubricating circuit for said engine, a valve head positioned upon said combustion and said pumping cylinders, valve means within said head for controlling the flow of a combustible mixture through said cylinders, a rotatable cam means positioned within. said head and interconnected with said valve means for timing the operation of said valve means, means drivingly engaging said timing cam and positioned within said valve .'head, means interconnecting said time cam driving means with said engine, and means for connecting said valve head within the fluid lubricating circuit for said engine to cause lubricant from the engine to flow through said valve head and lubricate said timing cam and driving means therefor.

14. In a two-stroke-cycle internal combustion engine, combustion cylinder, a power piston therein, a pumping cylinder parallel thereto, a4

pumping piston therein operating in step with said power piston, a iluid lubricating circuit for said engine, a common cylinder head for said cylinders, an inlet valve in said head for said pumping cylinder, intake and exhaust valves in said head for said combustion cylinder, a transfer passageway in said head connecting said cyliders and valved by said intake valve, a cam member rotating aboutan axis parallel to the axes of said valves and timed with respect to the movement of said-pistons for operating said valves and means 'for` connecting said cylinder head within the fluid lubricating circuit for said engine to cause lubricant from the engine to ow therethrough.

EARNEST M. LINDSEY. 

